2 Answers
2

The reason for this is that the salesforce.com email servers still
process the email and thus the bulk load is still on SFDC side. Once
processed the email is then passed (or relayed) to your email server
before sending.

These limits are enforced so that the load does not become too large
for sfdc servers to handle and cause performance issues for other
customers

In order to make yourself Unlimited while sending or scheudling the Mass Emails in Salesfroce or doing single emails to Contacts, Leads, sending emails to Campaign Members then you need to check an appexchange native app – Massmailer.This will let you bypass salesforce mass email limits and at the same time let you send simple marketing emails to Schedule one-off mass emails.
Check out the following link: MassMailer App Link on AppExchange
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